A pearl results from a mollusk's natural defense against a foreign particle and is formed by isolating the particle within a hardened secretion referred to as a nacre. The particle acts as an irritant and stimulates secretion of the viscous substance which hardens into the nacre coating. The desirability of pearls has lead to their widespread cultivation within a variety of mollusks. Among these Pinctada fucata, Pinctada maxima, Pictanda margaritifera have become some of the more popular sources for pearl production however mollusks such as abalone, conch and others are also currently used to produce highly sought after pearls.
Because of the desirability of pearls, multiple procedures have been developed to produce superior pearls for the jewelry industry. These techniques primarily involve incubating within a mollusk a nucleus constructed from shell powder or other non-precious material. A technology disclosed in U.S. Pat. No. 4,783,975 has taken this one step further by producing a colored pearl. This technology involves incubating within a mollusk waste shell material with an inorganic dye as a nucleus. Although a variety of single colors may be produced, this technique is limited to a single colored pearl and does not incorporate an exposed nucleus or carving.
Alternative technologies have been developed to produce pearls having unusual characteristics. For example, WO 00/13540 describes a process where an inlay is physically inserted into a cultured pearl. This process requires obtaining a pearl, removing a surface groove from the nacre coating such that an inlay element may be placed generally along the surface of the nacre coating, and anchoring the inlay within the groove. However because the inlay element is inserted after the pearl is produced, this technique is limited to a pearl that exposes the entire outer surface of the inlay element and is limited by the shape of the inlay element.
Decorating the surface of a pearl has been disclosed in Japanese patent publication #2002101921. This technique involves obtaining a pearl, engraving a surface groove along the nacre coating and affixing a decorative material such as a pigment or gold dust in the groove. Excess material is removed from the outer pearl surface and a coating such as a clear resin is applied. However this method does not provide for an exposed nucleus and is limited to materials that may be inserted into a surface groove.